Security system and method to detect concealed items

ABSTRACT

A security system to detect a concealed item carried by a traveler in motion, the security system includes a camera configured to capture an image series of the traveler in a Eulerian or Lagrangian frame of reference, wherein the captured image series contains motions generated by the concealed item; an alarm system configured to produce an alert signal; and an electronic control unit. The electronic control unit is configured to magnify motions generated by the concealed item to generate perceptible motions, provide an output image series that contains the perceptible motion, detect characteristic kinematic behaviors of the concealed item from the output image series, measure characteristic kinematic quantities of the characteristic kinematic behaviors, determine a presence of the concealed item from the characteristic kinematic quantities, and activate the alarm system to produce the alert signal.

BACKGROUND

The present disclosure relates generally to the detection of forbiddenitems that may be concealed by travelers, or personnel in areas undersecurity control, such as public transportation, public areas, andentrances to public or government buildings.

The detection of dangerous items that may pose a threat for security,e.g. firearms, explosives or knives, is probably the most crucial partof many security programs. Such detection is particularly relevant forsituations where there is an intense circulation of persons inside aconfined area and where these dangerous items may easily be hidden underclothing, such as the traffic of travelers carrying coats and/or jacketsthrough an airport security checkpoint.

Having an efficient and reliable way to detect concealed items duringperiods of intense traffic of persons can be extremely difficult.

Radiographic screenings, utilizing technologies such as x-raybackscatter and millimeter wave scanning, have long been known andwidely used to make detection of concealed items possible.

While radiographic images resulting from radiographic screening providesa way to detect concealed items carried by the travelers, radiographicscreenings rely on heavy machineries, require screening of the travelersone by one, and in most circumstances the person must stop for ascreening. All of which may be time and cost consuming.

Thus, a security system and a method to detect concealed items solvingthe aforementioned limitations is desired.

SUMMARY

Accordingly, the object of the present disclosure is to provide asecurity system and a method to detect concealed items, which overcomesthe above-mentioned limitations. The security system and the method ofthe present disclosure address the limitation of efficiency by providinga process to analyze videos of people and magnify small motionsgenerated by the concealed item that would be otherwise undetectablethrough the naked eye.

In one non-limiting illustrative example, a security system to detect aconcealed item is presented. The security system to detect a concealeditem includes a camera configured to capture an image series of thetraveler in an Eulerian or Lagrangian frame of reference, wherein thecaptured image series contains motions generated by the concealed item;an alarm system configured to produce an alert signal; and an electroniccontrol unit. The electronic control unit is configured to magnifymotions generated by the concealed item to generate perceptible motions,provide an output image series that contains the perceptible motion,detect characteristic kinematic behaviors of the concealed item from theoutput image series, measure characteristic kinematic quantities of thecharacteristic kinematic behaviors, determine a presence of theconcealed item from the characteristic kinematic quantities, andactivate the alarm system to produce the alert signal.

In another non-limiting illustrative example, a method to detect aconcealed item is presented. The method to detect a concealed itemincludes: capturing an image series of the traveler, via a camera,wherein the captured image series contains motions generated by theconcealed item; magnifying the motions generated by the concealed itemto generate perceptible motions, via the processing circuitry; providingan output image series that contains the perceptible motion, via theprocessing circuitry; detecting characteristic kinematic behaviors ofthe concealed item from the output images series, via the processingcircuitry; measuring characteristic kinematic quantities of thecharacteristic kinematic behaviors, via processing circuitry;determining a presence of the concealed item from the characteristickinematic quantities, via the processing circuitry; and producing analert signal via an alarm system.

BRIEF DESCRIPTION OF THE DRAWINGS

To easily identify the discussion of any particular element or act, themost significant digit or digits in a reference number refer to thefigure number in which that element is first introduced.

FIG. 1 is a schematic view of a security system to detect a concealeditem carried by a traveler, according to certain aspects of thedisclosure;

FIG. 2 is a flow chart of a detection method to detect the concealeditem carried by the traveler, according to certain aspects of thedisclosure;

FIG. 3 is a chart flow of a magnification method to magnify smallmotions produced by the concealed item of the traveler, according tocertain aspects of the disclosure; and

FIG. 4 is a schematic view of a hardware diagram of an electroniccontrol unit of the security system, according to certain aspects of thedisclosure.

DETAILED DESCRIPTION

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety.Further, the materials, methods, and examples discussed herein areillustrative only and are not intended to be limiting.

In the drawings, like reference numerals designate identical orcorresponding parts throughout the several views. Further, as usedherein, the words “a”, “an”, and the like include a meaning of “one ormore”, unless stated otherwise. The drawings are generally drawn not toscale unless specified otherwise or illustrating schematic structures orflowcharts.

FIG. 1 is a schematic view of a security system 100 to detect aconcealed item 210 carried by a traveler 200, according to certainaspects of the disclosure.

The security system 100 may include a camera 110, an electronic controlunit 300, and an alarm system 150. The camera 110 may capture inputimage series 130 of the traveler 200 in motion. The input image series130 may be collections of images captured successively in time, e.g.standard videos, of the traveler 200 in motion, e.g. walking or running.

The input image series 130 may be captured via an Eulerian frame ofreference and/or a Lagrangian frame of reference. In the Eulerian frameof reference, the traveler 200 passes through a field of view of thecamera 110 that is fixed. For example, the camera 110 may be affixed toa ground surface on which the traveler 200 is walking. In the Lagrangianframe of reference, the field of view moves with the traveler 200. Forexample, the camera 110 may be motorized to follow displacement of thetraveler 200 e.g. to follow the traveler 200 as he/she is in motion.

The electronic control unit 300 may receive the input image series 130from the camera 110 and apply a detection method S100 to the input imageseries 130 in order to reveal the presence of the concealed item 210, asdescribed in further detail below with regard to FIGS. 2 and 3.

The detection method S100 may include extracting small motions 212generated by the concealed item 210 carried on the traveler 200, e.g.motions with low spatial displacements that are not directly perceptibleby the naked eye, and magnifying the small motions 212 via amagnification method S140 to extract characteristic kinematic behaviorsand kinematic quantities of the small motions 212. For example, thecharacteristic kinematic behaviors may be rigid body motions such asrigid body rotations and/or translations and the kinematic quantitiesmay be the moments generated by the rigid body motions. For example, arigid body such as a concealed object may be revealed by an outline onthe overlaying garment, the constrained motion of the overlayinggarment, or an unnatural draping of the garment.

The concealed item 210 carried by the traveler 200 may be any item orobject that may pose a threat for security, e.g. a weapon or anexplosive, and that is prevented from being seen with an outer garment.For example, the concealed item 210 may be a handgun carried on a beltand covered by a shirt of the traveler 200.

The alarm system 150 may be activated by the electronic control unit 300to provide an alert signal 154 that indicates a presence of theconcealed item 210 on the traveler 200.

The alert signal 154 may be an acoustic signal produced by sirens and/orspeakers of the electronic unit 300, a visual signal produced by lightsources, and/or the combination of acoustic, visual and written messagesproduced by processing circuitry of the electronic control unit 300 anddisplayed on a monitor 314 of the electronic control unit 300.

Alternatively, the alert signal 154 may be messages containinginformation about the traveler 200, e.g. pictures of the traveler 200sent to authorities 400 responsible for the security of travelers. Forinstance, the authorities 400 may correspond to any group of personsenforcing security at a security checkpoint, such as agents ofTransportation Security Administration (TSA).

The alert signal 154 may be sent directly and confidentially to theauthorities 400 through a private network 3224, such as the Internet ora local intranet, via a network interface 326 of the electronic controlunit 300.

In addition, the alarm system 150 may be peripheral to or part of theelectronic control unit 300.

FIG. 2 is a flow chart of the detection method S100 for revealing thepresence of the concealed item 210 carried by the traveler 200,according to certain aspects of the disclosure.

In a step S110, the electronic control unit 300 receives the input imageseries 130 of the traveler 200 captured by the camera 110.

The input image series 130 may be captured at a predetermined frame rateFr and with a predetermined resolution R, wherein the predeterminedframe rate Fr and the predetermined resolution R are sufficiently highto substantially capture the small motions 212 produced by the concealeditem 210. Frame rates of 30 frames per second are baseline butinformation obtained from higher speeds can be overlaid to provide areasof time resolution. Frame rates of hundreds of frames per second areused to obtain data for humans walking at a few miles per hour toprovide millimeter resolution in space e.g. Fr=400 Hz. The predeterminedresolution R may correspond to a number of pixels sufficiently high tocompletely sample the concealed item 210, e.g. R=640×480 pixels.

In addition, the input image series 130 may be captured via the Eulerianframe of reference or via the Lagrangian frame of reference in stepS110.

In a step S120, for each image contained in the input image series 130,a specific region of interest 132 is selected and extracted in order toremove irrelevant motions and/or noises that may perturb the applicationof the detection method S100. For example, irrelevant motions or noisesmay include untargeted objects and/or travelers. The specific region ofinterest 132 may correspond to a sensitive zone and/or part of thetraveler 200 where the concealed item 210 may be carried, e.g. a waist,legs, armpits, or forearms of the traveler 200.

The step S120 may be performed manually via the authorities 400 orautomatically via software instructions executed by a processor 302including processing circuitry inside the electronic control unit 300.For example, the authorities 400 may select a group of pixels for eachimage of the input image series 130 via a command/instruction interfaceof the electronic control unit 300, or the software instructions mayapply a digital mask to each image of the input image series 130.

In a step S130, the input image series 130 is decomposed into aplurality of spatial frequency bands. Then, the pixel value time series134 corresponding to the values of a pixel in each spatial frequencyband of the plurality of spatial frequency bands is extracted.

The step S130 may be performed automatically via software instructionsexecuted by the processor 302 including processing circuitry inside theelectronic control unit 300. For example, the software instructions mayrely on image processing tools, such as fast Fourier transforms.

In a step S140, the magnification method S140 is applied to the pixelvalue time series 134 in order to obtain magnified pixel value timeseries 138 by constructing and implementing a temporal filter and amagnification function α to the pixel value time series 134. Theconstruction of the temporal filter and the magnification function α maybe performed by selecting from a library different types of filters, anddifferent types of amplification function α. The different types offilters may include Gaussian filters, first-order low pass InfiniteImpulse Response (IIR) filters, comparison filters of adjacent areas,spatial filters, or symmetry comparisons of the image. The differenttypes of magnification function α may include step functions, orexponential functions, wherein the library is stored in a memory 304 ofthe electronic control unit 300. The step S140 is described in furtherdetails in FIG. 3, which depicts the magnification method to magnifysmall motions 212 produced by the concealed item 210, and the followingparagraphs.

In a step S150, the magnified pixel value time series 138 is added tothe pixel value time series 134 to generate a super imposed pixel valuetime series. An output image series S140 is generated by applying aspatial reconstruction, e.g. inversion of the spatial decompositionperformed in the step S130, to the super imposed pixel value timeseries.

The step S150 may be performed automatically via software instructionsexecuted by the processor 302 including processing circuitry inside theelectronic control unit 300. For example, the software instructions mayrely on inverse fast Fourier transform.

In a step S160, it is determined if the concealed item 210 displayscharacteristic kinematic behaviors, e.g. rigid body motions, orasymmetric motions

If it is determined in step S160 that the concealed item 210 displaysthe characteristic kinematic behaviors, the process goes back to thestep S110 to select a different region of interest. Otherwise, theprocess continues to a step S170.

The detection of the characteristic behaviors may be performed manuallyvia the authorities 400 and/or automatically via software instructionsexecuted by the processor 302 including processing circuitry inside theelectronic control unit 300. For example, the authorities 400 mayvisually analyze the output image series 140 displayed on the monitor314 via the naked eye and/or the software instructions may performanalysis on the output image series 140 to detect and track in time agroup of connected pixels that displays the characteristic kinematicbehaviors.

In the step S170, characteristic quantities associated with thecharacteristic behaviors are measured such as a moment of the rigid bodymotion τ. The measurement of the characteristic quantities may beperformed automatically via software instructions executed by theprocessor 302 including processing circuitry inside the electroniccontrol unit 300. For example, the software instructions may calculatethe moment of the rigid body motion T associated to the group ofconnected pixels that has been tracked in time in the step S160.Pre-computed models that provide kinematic markers obtained frompreviously completed person-object walking models may also be used toassess kinematic behaviors.

In a step S180, it is determined if the characteristic behaviors aresufficiently important to represent a threat to security by comparingthe characteristic quantities that had been measured in the step S170 topredetermined threshold values. For example, the rigid body motion isdetermined to pose a threat for security if the moment of the rigid bodymotion τ is higher than a predetermined torque threshold value τ0.

If it is determined that the characteristic kinematic behavior aresufficiently important to represent a threat for the security in stepS180, the process goes to a step S190. Otherwise, the process goes backto the step S110 to receive subsequent input image series 130.

In the step S190, a command to produce the alert signal 154 is sent bythe electronic control unit 300 to the alarm system 150.

In addition, software instructions may be executed by the electroniccontrol unit 300 to directly and confidentially send the alert signal154 to the authorities 400 via the network interface 326 of theelectronic control unit 300.

The region of interest 132 may be divided into a plurality ofsub-regions, wherein each sub-region may be iteratively and individuallyprocessed from the step S132 to the step S180 via software instructionsexecuted by the processor 302 including processing circuitry inside theelectronic control unit 300. Alternatively, all the sub-regions of theplurality of sub-regions may be simultaneously processed from the stepS130 to S180 by using at least one graphic processing unit or processingcircuitry of the electronic control unit 300 in a parallel computingconfiguration.

FIG. 3 is a chart flow of the magnification method S140 to magnify thesmall motions 212 produced by the concealed item 210 of the traveler200, according to certain aspects of the disclosure.

In a step S142, the temporal filter is constructed to target and extractthe small motions 212 generated by the concealed item 210.

For example, the temporal filter may be a temporal bandpass filterconstructed to focus on a relevant band of frequencies in which thesmall motions 212 occur. The relevant band of frequencies may becentered on a key frequency w_(k) that captures the small motions 212generated by the concealed item 210. For example, the key frequencyw_(k) may be the number of steps per second executed by the traveler200.

The temporal bandpass filter may be constructed via a first first-orderlowpass IIR filter with a first cutoff frequency w₁ and a secondfirst-order lowpass IIR filter with a second cutoff frequency w₂,wherein the first cutoff frequency w₁ is lower than the key frequencyw_(k) and the second cutoff frequency w₂ is higher than the keyfrequency w_(k).

The step S142 may be performed manually via the authorities 400 and/orautomatically via software instructions executed by the processor 302including processing circuitry inside the electronic control unit 300.

In a first example, the authorities 400 may manually select a type oftemporal filter from the library, e.g. the temporal bandpass filter, andmanually enter the parameter values corresponding to the selected typeof temporal filter, e.g. the values of the first cutoff frequency w₁,the key frequency w_(k), and the second cutoff frequency w₂, via thecommand/instruction interface of the electronic control unit 300.

In a second example, the software instructions may be configured toselect a default type of temporal filter from the library stored in thememory 304 of the electronic control unit 300. The default type may be atemporal bandpass filter, with corresponding default parameter values,the values of the first cutoff frequency w₁, the key frequency w_(k),and second cutoff frequency w₂. The exemplary values for the centraltemporal bandpass filter may be on the order of 1/10 of the frame rateFr. The bandpass, or w1 and w2, may be symmetric about the centralfrequency and be 1/20 of the Fr.

In addition, via the software instructions, the selection of the typetemporal filter and corresponding parameter values may be performediteratively until the concealed item 210 is detected, by performing adata sweeping over the different types of temporal filter andcorresponding parameters contained in the library.

In a step S144, the temporal filter constructed in the step S144 may beapplied to the pixel value time series 134, via software instructionsexecuted by the processor 302 including processing circuitry inside theelectronic control unit 300, to obtain a filtered pixel value timeseries having the relevant band of frequencies.

In a step S146, the magnification function α is constructed to furthertarget and amplify the small motions 212 that have been filtered in thestep S144.

For example, the magnification function α may be a step function thatdepends on the spatial frequency of the filtered pixel value timeseries. The step function may be constructed with an attenuation α_(a)that forces the amplification to go from a maximum amplification α_(m)to zero when the spatial frequency exceeds a critical spatial frequencyλ_(c).

The step S146 may be performed manually via the authorities 400 and/orautomatically via software instructions executed by the processor 302including processing circuitry inside the electronic control unit 300.

In a first example, via the command/instruction interface of theelectronic control unit 300, the authorities 400 may manually select thetype of the magnification function α from the library, e.g. the stepfunction, and manually enter the parameter values corresponding to theselected type of the magnification function α, e.g. for an a value of 1,the critical spatial frequency λ_(c) may be 4 divided by the pixeldimension, and the maximum amplification factor α_(m).

In a second example, the software instructions may be configured toselect a default type for the magnification function α and correspondingdefault parameter values from the library stored in the memory 304 ofthe electronic control unit 300.

In addition, via the software instructions, the selection of the type ofmagnification function α and corresponding parameter values may beperformed iteratively until the concealed item 210 is detected byperforming a data sweeping over the different types of magnificationfunction α and corresponding parameters contained in the library.

In a step S148, the magnification function α constructed in the stepS146 is applied to the filtered pixel value time series via softwareinstructions executed by the processor 302 including processingcircuitry inside the electronic control unit 300, to obtain themagnified pixel value time series 138.

In an alternative aspect of the disclosure, the magnified pixel valuetime series 138 obtained from the input image series 130 captured viathe Eulerian frame of reference may be compared and correlated to themagnified pixel value time series 138 obtained from the input imagesseries 130 captured via the Lagrangian frame of reference in order tobetter magnify the small motions 212 and better detect the concealeditem 210. Translation between Eulerian and Lagrangian frames ofreference can better capture a wide variety of motions: a Lagrangianframe of reference better enhances motion of sharp objects with largeramplification factors, while a Eulerian frame of reference is better atcapturing smooth structures and small amplification factors.

FIG. 4 is a schematic view of a hardware diagram of the electroniccontrol unit 300 of the security system 100, according to certainaspects of the disclosure

FIG. 4 depicts the electronic control unit 300 to control the apparatusto process the input image series 130, project output image series 130to monitor, and if necessary, send a command to produce alert signal 154to alert system 150. As shown in FIG. 4, systems, operations, andprocesses in accordance with this disclosure may be implemented using aprocessor 302 or at least one application specific processor (ASP). Theprocessor 302 may utilize a computer readable storage medium, such as amemory 304 (e.g., ROM, EPROM, EEPROM, flash memory, static memory, DRAM,SDRAM, and their equivalents), that is configured to control theprocessor 302 to perform and/or control the systems, operations, andprocesses of this disclosure. Other storage mediums may be controlledvia a disk controller 306, which may control a hard disk drive 308 oroptical disk drive 310.

The processor 302 or aspects thereof, in an alternate embodiment, mayinclude or exclusively include a logic device for augmenting or fullyimplementing this disclosure. Such a logic device includes, but is notlimited to, an application-specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), a generic-array of logic (GAL), andtheir equivalents. The processor 302 may be a separate device or asingle processing mechanism. Further, this disclosure may benefit fromthe parallel processing capabilities of a multi-cored processor.

In another aspect, the results of processing in accordance with thisdisclosure may be displayed via a display controller 312 to the monitor314 that may be peripheral to or part of the electronic control unit300. Moreover, the monitor 314 may be provided with a touch-sensitiveinterface to a command/instruction interface. The display controller 312may also include at least one graphic processing unit for improvedcomputational efficiency. Additionally, the electronic control unit 300may include an I/O (input/output) interface 316, provided for inputtingsensor data from sensors 318 and for outputting orders to actuators 322.The sensors 318 and actuators 322 are illustrative of any of the sensorsand actuators described in this disclosure, such as the camera 110 andthe alarm system 150.

Further, other input devices may be connected to an I/O interface 316 asperipherals or as part of the electronic control unit 300. For example,a keyboard or a pointing device such as a mouse 320 may controlparameters of the various processes and algorithms of this disclosure.They also may be connected to the I/O interface 316 to provideadditional functionality and configuration options, or to controldisplay characteristics. Actuators 322 which may be embodied in any ofthe elements of the apparatuses described in this disclosure may also beconnected to the I/O interface 316.

The above-noted hardware components may be coupled to the network 324,such as the Internet or a local intranet, via a network interface 326for the transmission or reception of data, including controllableparameters to a mobile device. A central bus 328 may be provided toconnect the above-noted hardware components together, and to provide atleast one path for digital communication therebetween.

The foregoing discussion discloses and describes merely exemplaryembodiments of an object of the present disclosure. As will beunderstood by those skilled in the art, an object of the presentdisclosure may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. Accordingly, thepresent disclosure is intended to be illustrative, but not limiting ofthe scope of an object of the present disclosure as well as the claims.

Numerous modifications and variations on the present disclosure arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the disclosuremay be practiced otherwise than as specifically described herein.

What is claimed is:
 1. A security system to detect a concealed itemcarried by a traveler in motion, the security system comprising: acamera configured to capture an image series of the traveler in one ofan Eulerian frame of reference and a Lagrangian frame of reference,wherein the captured image series contains motions generated by theconcealed item; an alarm system that produces an alert signal; and anelectronic control unit configured to: magnify the motions generated bythe concealed item to generate frame of reference perceptible motions;detect characteristic kinematic behaviors of the perceptible motions;measure characteristic kinematic quantities of the characteristickinematic behaviors; determine a presence of the concealed item from thecharacteristic kinematic quantities; and activate the alarm system toproduce the alert signal.
 2. The security system of claim 1, wherein theelectronic control unit is further configured to: extract a pixel valuetime series for each image of the input image series; and apply amagnification function to the pixel value time series; wherein themagnification function depends on spatial frequencies of the pixel valuetime series.
 3. The security system of claim 2, wherein themagnification function provides a maximum amplification when the spatialfrequencies are lower than a critical spatial frequency and anattenuation when the spatial frequencies exceed the critical spatialfrequency.
 4. The security system of claim 2, wherein the electroniccontrol unit is further configured to apply a bandpass filter to thepixel value time series.
 5. The security system of claim 4, wherein thebandpass filter has a pass band that is centered on a key frequency ofthe traveler in motion.
 6. The security system of claim 5, wherein thebandpass filter is constructed with a first first-order lowpass infiniteimpulse response filter having a first cutoff frequency and a secondfirst-order lowpass infinite impulse response filter having a secondcutoff frequency.
 7. The security system of claim 1, wherein thecharacteristic kinematic behaviors include rigid body motions.
 8. Thesecurity system of claim 7, wherein the characteristics kinematicquantities include moments of the rigid body motions.
 9. The securitysystem of claim 1, wherein the electronic control unit is furtherconfigured to select a specific zone of interest for each image of thecaptured image series.
 10. The security system of claim 1, wherein theelectronic control unit is further configured to alert authorities inresponse to the alert signal.
 11. A method to detect a concealed itemcarried by a traveler in motion, the method comprising: capturing animage series of the traveler in one of an Eulerian frame of referenceand a Lagrangian frame of reference, via a camera, wherein the capturedimage series contains motions generated by the concealed item;magnifying the motions generated by the concealed item, via theprocessing circuitry, to generate perceptible motions; detectingcharacteristic kinematic behaviors of the perceptible motions, via theprocessing circuitry; measuring characteristic kinematic quantities ofthe characteristic kinematic behaviors, via processing circuitry;determining a presence of the concealed item from the characteristickinematic quantities, via processing circuitry; and producing an alertsignal via an alarm system.
 12. The method of claim 11, furthercomprising: extracting pixel value time series for each image of thecaptured image series, via the processing circuitry; and applying amagnification function to the pixel value time series, via processingcircuitry; wherein the magnification function depends on spatialfrequencies of the pixel value time series.
 13. The method of claim 12,wherein applying the magnification function further includes providing amaximum amplification, via the processing circuitry, when the spatialfrequencies are lower than a critical spatial frequency and anattenuation when the spatial frequencies exceed the critical spatialfrequency.
 14. The method of claim 12, wherein extracting the pixelvalue time series further includes applying a bandpass filter to thepixel value time series, via the processing circuitry.
 15. The method ofclaim 14, wherein the bandpass filter has a pass band that is centeredon a key frequency of the traveler in motion.
 16. The method claim 15,wherein the bandpass filter is constructed with a first first-orderlowpass infinite impulse response filter having a first cutoff frequencyand a second first-order lowpass infinite impulse response filter havinga second cutoff frequency.
 17. The method of claim 11, wherein thecharacteristic kinematic behaviors include rigid body motions.
 18. Themethod of claim 17, wherein the characteristics kinematic quantitiesinclude moments of the rigid body motions.
 19. The method of claim 11,further includes selecting a specific zone of interest for each image ofthe input image series, via the processing circuitry.
 20. The method ofclaim 11, further includes alerting the authorities, via a networkinterface of the electronic control unit, in response to the alertsignal.